1. Field of Invention
The present invention relates to a touch panel. More particularly, the present invention relates to a touch panel and its peripheral circuit.
2. Description of Related Art
Recently, flat-panel displays with small volumes have become the displays popularly used in various electronic products. In order to achieve the objects of operation convenience, concise appearance and integrated functions, many information products have been switched to using a touch panel as an input device from traditional input devices such as a keyboard, a mouse, etc.
With the advanced developments of flat-panel displays and touch-control input devices, in order to allow a user to have a larger viewable image and more convenient operation modes under a limited space, some electronic products have combined the touch panel with the display panel as a touch display panel. Since having the display function of the display panel and the operation convenience using the touch panel for input, the touch display panel has gradually become an important option to various electronic products such as a handheld personal computer (PC), a personal digital assistance (PDA) and a smart phone, etc.
The operation mode of the touch panel is described hereinafter. When a conductive article (such as a finger) touches a touch sensor array of the touch panel, an electrical property (such as an electrical resistance value or capacitance value) will be changed accordingly, thus causing the touch sensor array to have a bias change. The change of the electrical property will be transformed to a control signal, and the control signal will be transmitted to an external control circuit board for being processed and computed by a central processing unit (CPU) to obtain a result. Thereafter, a display signal will be outputted to a display panel via the external control circuit board, thereby displaying an image to a user. The stability and reliability of touch signal transmission determined whether the action of the touch panel is correct. Therefore, the stability and reliability of signal transmission between the touch panel and the external electrical circuit is an important issue to touch the panel industry.